Dehino 'smin yathā dehe kaumāraṁ yauvanaṁ jarā: "The body is sometimes child and sometimes boy, sometimes young man, sometimes old man. So the body is changing." Who cannot understand this? The child, the small child, is dancing. Now, that child will get the body of a young man like you. Everyone knows it. This body will change. Where is the difficulty? And Kṛṣṇa is giving this common example, tathā dehāntara-prāptiḥ (BG 2.13). As you are experiencing this change of body, similarly, you take it that this body also will change. An old man like me, the next body is there. Either farther old man or, after death, another body. This is to be understood. Tathā dehāntara-prāptiḥ. Dehāntara-prāptiḥ means to get another body.
So we are experiencing in our this life. It is taking change so swiftly that we cannot understand how the body is changing, but it is changing. So similarly, this body will change, tathā dehāntara-prāptiḥ. And we have to change that body after death according to my mental condition, because we have got two bodies, the subtle body and the gross body. This gross body is finished; it is no more working. Just like at night the gross body does not work. We are thinking, "I am sleeping." Sleeping means the body is so much tired, it is no more working. But your another body, which is made of mind, intelligence and ego—subtle body—that is working. Everyone has got this experience. The subtle body takes you to another place or another condition.